1. Field of the Invention
The present invention relates to a control system in a test device for testing a manual speed change unit. More particularly, it relates to a control system in a test device for testing a manual speed change unit which is mounted on vehicles and so on and which is provided with an input shaft driving means for forcibly driving the input shaft of the manual speed change unit and a clutch unit placed between the input shaft driving means and the input shaft of the manual speed change unit.
2. Description of The Prior Art
The conventional control system in a test device will be described with reference to FIG. 1.
An input shaft driving means (1) such as a motor is connected to a manual speed change unit (3) (referred to as a work hereinbelow) through a clutch (2) and a torque detector (5) and a speed detector (6) for detecting speed of the input shaft driving means are respectively connected to the input shaft driving means (1). The output of a reference torque signal producer (7) is input into a torque operating device (9) along with the output of the torque detector (5), while both outputs of a reference speed signal producer (8) and the speed detector (6) are input into a speed operating device (10). Reference data from the reference torque signal producer (7) and measured data from the torque detector (5) are input in the torque operating device (9) to compare both the data and the reference data from the reference speed signal producer (8) and measured data from the speed detector (6) are also input in the speed operating device (10) to compare both the data. The outputs thus compared are respectively input into a controlling unit (12) through switching operations of a switch (11) whereby a power source unit (13) for the input shaft driving means (1) is controlled. The switch (11) is operated such a manner that the torque operating device (9) is connected to the controlling unit (12) when the clutch (2) is in a connecting state and the speed operating device (10) is connected to the controlling device (12) when the clutch (2) is in a disconnecting state. An output shaft, a coupling device (14) and an absorbing apparatus (4) such as a motor are connected to the work (3) on the output side. The reference number (15) designates an input shaft of the work (3).
FIG. 2 shows variations of the revolution number of the input shaft (15) and the output shaft (14) of the work for each position of the gear shift of the manual speed change unit (3).
The method of controlling the revolution speed of the input shaft driving means (1) in the test device described above will be explained with reference to FIG. 2.
When the work (3) is rotated at the first speed, the revolution number of the output shaft (14) is raised to the point A by a speed control. Thus, the speed control in a certain shift position can be carried out by controlling the revolution speed of the motor when it is used as the absorbing apparatus (4). Then, the revolution number of the input shaft (15) of the work reaches the point .alpha..A, assuming that the first speed gear ratio of the work (3) is a constant .alpha.. When the speed is changed to the second speed by disconnecting the clutch (2) and changing a gear shift, the revolution number of the work input shaft (15) decreases to the point .beta..A, assuming that the second speed gear ratio of the work (3) is a constant .beta.. It is, therefore necessary to reduce the revolution number of the input shaft driving means (1) to the level corresponding to the point .beta..A. This is because wearing of the clutch increases if the clutch is connected under the condition that the revolution number of the work input shaft (15) is not coincident with that of the input shaft driving means (1). The same condition applys the change of the gear shift to the third speed or other grade of speed.
In the conventional system, therefore, it has been required to determine a reference revolution number at the speed changing point for each time that the manual speed change unit (3) is subjected to the change of the gear shift under the condition of the clutch (2) disconnected. Accordingly, the reference speed signal producer (8) has been needed to control the revolution speed of the input shaft driving means (1). Namely, when the position of gear shift is changed from the first speed to the second speed, the reference speed signal producer (8) generates the reference signal corresponding to the revolution number at the point .beta..A as shown in FIG. 2.
Thus, in the conventional test device using the control system described above, a reference speed signal producer is needed for an input shaft driving means thereby causing a higher manufacturing cost and a large-sized device.